Process for making phonograph-blanks.



PATENTED JUNE 4, 1907.

3'. W. AYLSWORTH.

PROCESS FOR MAKING PHONOGRAPH BLANKS.

' APPLIOATION FIL'ED JAN. 19, 1907.

UNITED srA'r as PATENT orrron.

JONAS W. AYLSWORTH, OF EAST OEA NGE, NEW JERSEY, ASSIGNOR To NEW JERSEYPATENT COMPAN Y, .OF WEST ORANGE, NEW JERSEY, A CORPO-.

RATION OF NEW JERSEX.

PROCESS FOFUMAKING PHONOGRAPH BLANKS.

Specification of Letters Patent.

Patented June 4, 1907.

Application filed Kanuary 19, 190']. Serial No. 353,007.

,graph-Blanks, of which the following is ade- I soription.

My invention relates to animproved roce'ss for manufacturing'blankrecord ta lets i for use on phonographs and allied talking mathines inwhich cylindrical blanks are employed, and my object is to provide aprocess y which the blanks may e manufactured economically and whereinthe recording surface will be of a uniformly perfect character.

As phonograph blanks are now commer- Q1. cially made, they are formed ofa homogene- \ous metallic soap composition consisting en- 0' er lly ofstearate of soda, stearate ofalumina,

fre stearic acid and a hydrocarbon ingredi- (ent such as paraffin orceresin. The aim of the manufacturer is to produce the composition in aspure a form as possible, and to this end the operations are carried onwith cat care and the composition after being finished is generallysubjected to one or more filtrations. Notwithstanding these precautions,however, the composition frequently contains minute gas bubbles as wellas mechanical impurities, such as dust particles, small pieces of lintand crystals of saline impurities. These impurities when they appearonthe surface of the blanks result in an imperfect record which cannotbe effectively used as a master from which to make a moldfor-duplicating purposes. The encountering of these small imperfectionsin the blanks is annoying and expensive under conditions of commercialmanufacture since in making the master a very ex ensive artist may beemployed or an entire )and or orchestra yet the presence of a singlepiece of lint in the record surface or other imperfection therein, willresult in the formation of a socalled blind, necessitatilng thediscarding of the record and a new tria In applications for LettersPatent filed May 11, 1906, Serial No. 316,250; May 16,

1906, Serial No. 317,083; May 16, 1906, Se.

rial No. 317,082, and May 31, 1906, Serial No. 319,422, I have describedcertain processes for manufacturing duplicate sound I {records frommatrices or molds consisting generally in rotating the mold at a highspeed. and introducing therein a char e of molten or comminuted wax-likemateria the mold being either hot'enough prior to the introduction ofthe material or being heated during its rotation so that the materialwill maintain its molten state, if introduced as such, or be renderedmolten ifintroduoed in comminuted condition. Byreason of the rotation ofthe mold at a high speed the molten ma-' terial will be distributeduniformly over its bore so as to take a clean and sharp-impression,after which the rotation of the mold is continued until the material hasbecome set,

and is finally removed by permitting it to contract-diametrically to asufiicient-extent to clear the engaging surface. This general process isof espec al utility in connection with the manufacture of phonographblanks, be

cause I have discovered that when the material in molten condition ismaintained in contact with the bore of a rotating mold, the centrifugaleffect is suficient to separate from the molten' material any foreignmatter acci-' dentally lodged therein. Such of the matter, as-I'iiay beof greater specific gravit than the composition, for instance, grit andirt, will be forced outward to the outer surface, on

the other hand, the material which is li hterthan the composition, suchas lint or gas ubb'les, will be dis laced by the composition 1 3. Afterthe mold has been and driven inwar rotated for about one minute at aspeed of two thousand revolutions per minute, the wax composition. beingmaintained in a molten state, an eflective'separation of the impuritieswill have taken place. The mold while still rotating is either allowedto cool or is forcibly chilled so as tocause the material to set andharden, whereu on the rotationmay be arrested. A furt er reduction. oftemperature effects a longitudinal con-.

traction of the blank, permitting its removal from the mold. The blankis now reamed on its-interior so as to fit the tapered mandrel of asuitable recording machine and is then sha'vedofi' on its exterior so asto present the desired diameter. The amount of material shaved off fromthe exterior of the blank should be of sufficient depth to include theheavier impurities which are driven out to' the surface. For this reasonthe molds it sulliciently to me purities, although this is not soimportant, will be,ob\'iouslv enwhich the blanks are made should beslightly larger than those now used, since the amount of material shavedoil will, to assure absolute certainty, be somewhat greater than is nowremoved under existing methods.

I In order that the invention may be better understood, attention isdirected. to the ac- 'compair\;'ing drawings forming part of thissectional view tus similar to the latter being rotated by a drivingroller It.

The mold! is shown as being provided with end caps 2, oneuot' which isremovahleso as to maintain the molten material avithin the mold duringits rotation. Any suitable means may be employed for introducing moltenmaterial within the mold,-as-t'or'example, aplun'ger pump -l mounted inatanlc 5, containing the molten materia'l.- lt'elerring to Fig. .2, Ishow the mold 2 as it appears when rotated ata high speed. the heavierparticles fi'being driven by centriYugaLl'orce.

because of their greater specilic gravit zto the exterior ol themoltenmaterial 7. and.

the lighter particles and bubbles being dis-. placed and forced inwt'erial- Alter the blank is seta the outer surface is shared oll be ticontaining the heavier impurities.-while preferably the innersurl'ace isreamed out.

nd removed.

heresulting blank tn'ely tree ol" unpuritics or nnpertections,on itsrecording surtaco. r r l 1 n v v 1 he composition nhiehl pltftl. toeniplo ard by the molten ma.

hide. all of the lighter ims l l l l i material.

this lNtli davol'tlanuarv ltlOT.

is that which is commonly used at the present time for making blanktablets and consists of the metallic soap mixture above generaltvdescribed.

Having now described my invention, what 1 claim as new, and desire tosecure bro-Letters latent, is as t'ollow's l. The process of nmking cvlindr' 'al-blank sists in rotating a hot mold at a high speed containing a charge of molten material within the same,"whereby the materialtherein will be distributed uniformly on its bore and a separation attheihipi'irities from the material will be ell'ected. in then allowing themold t't'rcool so'as to set the material, in then removing the blankfrom the mold. and in linallv shaving oll' the outer surface of theblank so as to thereb v removeany impurities which may he lodgedthere-in. substantially as .and an. the purposes set forth; 3

l. .lh.e process of making evlimlr-ical blank maelnnes which I moltl ata high,

record tablets for. talking consists 'ln'rotating a hot speedcontaining. a: c-hargeof molten uniterial within the same, whereby thematerial 7 tionon. its ,bore and a se aaration'of the, m- .purit ies,l'rom thcauaterial .therein will be distributed in. molten condrwill beetlectethin then allowing]hemold to oool;stj as 'to themold. inshavingoil' the the lilanhso' as to therebx; removeauy unlinishiug.theinteriorot the' blank, substantiallv.as.and,tor.thepurposes setfm-ph, I 8'0.-

-'l,his specification} signedfand witnessed \l'itness L FRAQJK l llv -aA v v Fnaxa l). la-zwis, v

record tablets l t rtalliing maehi'ncs which con.

set the, 1 in .then removmgthe blank from "outer surface" of uuitieswhich maybe lodged; therein, andin' i

